Choosing a mountain bike helmet is often, even for the most experienced riders, a very difficult experience. But an initial key decision needs to be made before looking at the infinite number of factors arising from the helmets’ different features: Open-face or full-face?
Some disciplines leave no room for doubt – open helmets for cross country and full-face helmets for downhill riding. In-between, however, lies a kind of gray area where all options are sound – they all have their own particular pros and cons, so that your choice will be determined, above all, by your riding style and preferences. Let's find out what are the advantages of either type of helmet.
Historically, open-face helmets have always been the most popular solution, although in recent years, with the exponential growth of trail and enduro bikes, this is not as clear cut as it used to be. However, the open-face helmets retain some particularly obvious advantages.
They don’t have a chinguard, and as such they will always be lighter than full-face helmets. The weight of a helmet is a factor to be taken into consideration, especially when you plan to spend many hours in the saddle. Although full-face helmets have now reached excellent standards in terms of weight, they are nonetheless a few hundred grams heavier than open-face helmets, something that can make a little difference when worn the whole day long. The Dainese's Linea 03 MIPS + barely reaches 340 grams in size M.
Moreover, due to the lack of a chinguard, open-face helmets clearly offer better ventilation. This is essential during the summer, when – especially riding uphill – feeling some fresh air on your face is a real pleasure. Still, front ventilation is not all that matters – rear ventilation from back and top openings is also important, and the Linea 03 MIPS + features 18 openings.
Another technical feature distinguishing open-face from full-face helmets is that the former have a ring nut on the back to adjust the fit’s width, so that you can customize it at any time or when, on a particularly cold day, you want to wear a cap underneath.
Full-face helmets are the most protective solution, also visually. Moreover, they are mandatory in competitions such as downhill or enduro races. The chinguard protects your face from all those potential impacts that can’t be mitigated with your hands. Not only that, it's also useful in protecting you from branches, stones or mud that can't be dodged while riding.
Inevitably, their weight will be higher than that of open-face helmets, but the latest full-face helmets – such as the Dainese Linea 01 MIPS – have reached levels that were inconceivable only a few years ago: A record weight of just 570 grams in size M.
In terms of ventilation, too, the most advanced full-face helmets are now very comparable to open-face helmets. The Linea 01 MIPS features 29 air vents. The airflow is noticeable even at low speeds and allows for maximum comfort and coolness during climbs.
Development of full-face helmets also focuses on the width of the field of vision and their integration with goggles, the preferred solution when using this type of protection. The chinguard is similarly designed so as not to restrict visibility at any time.
The peak is also rather relevant in full-face helmets. It has to be adjustable, so that you can tailor it to your own needs: Down for maximum protection against the elements – especially when it rains – or up for maximum visibility. The peak of the Linea 01 MIPS visor is easily adjusted with one hand, even on the go.
Having explained the major differences between the two solutions, there are some other features to look out for in a helmet, whether open-face or full-face. The main ones concern safety in the strictest sense.
All the same, inner shells are made of EPS (expanded polystyrene), a material that compresses in the event of an impact, absorbing part of the impact force. The most advanced and safest helmet models feature EPS shells with differentiated densities, placed according to the areas of the skull most susceptible and exposed to impact.
Inclusion of the MIPS® - Multi-directional Impact Protection System should also be considered. It’s been the ultimate system for oblique impact protection for the last ten years. This is a type of impact resulting in rotational head acceleration, one of the main causes of severe brain damage according to the latest studies in the sector. Oblique, or angular, impacts are the ones that occur most frequently in real life – it’s actually unlikely for an impact to occur perfectly perpendicular to the surface that absorbs it.
MIPS® technology works in a very simple way: This system allows to rotate the head inside the helmet, helping it to slide in relation to the outer shell through a sliding insert. This sliding dissipates some of the force of the impact, so the overall intensity of the impact transmitted to the head is drastically reduced. Helmets that incorporate this solution can be distinguished immediately through the yellow color of the insert, quickly identifiable by looking inside the helmet.
Owing to the latest technology, the TwiceMe® NFC system has been integrated into the most advanced bike helmets. It’s a chip, incorporated in both the Linea 01 MIPS and the Linea 03 MIPS +, that doesn’t require any batteries and allows you to upload all your personal and health information, which can be accessed through standard rescue devices, so that rescuers are able to immediately learn all essential information about the rider and drastically reduce first-aid response times.
Recco® is a device integrated in the Linea 03 MIPS + and it allows the rider to always be traced when lost or in an emergency situation. It consists of a reflector that is immediately detectable even in difficult conditions by standard rescue detectors.
Last but not least, the fastening system. An increasingly popular solution is the Fidlock® system, a magnet that allows the fastening strap to be closed and opened with just one hand. To close it, you simply bring the two ends of the strap closer together and the magnet fastens it. To open it, you just slide the two ends in the opposite direction.
The most traditional system is the buckle system, which is also quick to release with one hand, although you will need both to fasten it. The double-D strap, typical of motorcycle helmets, is not very common on trail and enduro helmets. This solution is universally adopted, however, on full-face downhill helmets, which are the most similar to motocross helmets.
Considering the broad spectrum of modern mountain bike disciplines, both open-face and full-face helmets can be valid choices. No matter what you choose, the important thing is that you make an informed decision and pay particular attention to all the factors that determine the overall safety of a helmet.